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Mini Q

Yep, Jer and I had a great time w/ the Mini-Q"s.
As far as cg mine was at 23mm, but I just moved it back to 25mm. Neutral was at 3mm.
Throws are up/down 2mm, Ails are up/down 8mm. Doesn't sound like like much, but it's on the verge of too much. all were at 20% expo.

Matt
 
Welcome Matt.

With that much reflex (3mm) and that little down elevator (2mm) how was the inverted flight?

Do you guys rig with a lot of reverse differential (mechanical or programatic) on the elevator (more down than up)?

All the best,
Konrad


Mirage 2000 airfoil 5.jpg
 
Konrad, this plane is not using a plank airfoil (reflexed) as far as I can tell, and that is why it requires the up elevator, you are modifying the airfoil to get the required reflex that should have been in the airfoil from the start. I was using the same up and down travel for my elevator. For differential, I do not recall having any, I usually dial in a little automatically, but the plane has such a tiny wing span I don't think you will notice much yaw even if you have no differential. Also, she has a big fin and flies pretty quick.
 
While my drawing is showing a "reflexed" airfoil. The concept for stability is the same with any other airfoil used with stabilizerless wings. That is that there needs to be some way to get low pressure aft and below the chord line. Whether this comes in a designed reflex or by rigging the TE up the effect is the same. (Ok, the efficiency is different).

The differential I'm concerned about is needing to remove the upright reflex and then adding in the inverted "reflex". Or what I call inverted trim. The amount of offset between these two trim states is what I call trim offset and is often controlled by the CofG. The more nose heavy the larger the trim offset. (Yes, the camber does account for there being less reflex need inverted if measuring from the chord line)

So from a steady upright trim (reflexed) if we want the same elevator feel (power) inverted we need to move the elevator a lot more in the downward direction from the upright trim condition. That is if we want the outside loops to look a lot like the inside loops. This is what I mean by elevator differential.

I think you are talking about aileron differential, which is for the classic yaw issue we see when using ailerons.
 
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Also please let us know how you liked inverted flight, response and forward stick pressure.

All the best,
Konrad
 
Hi Konrad
Sry my numbers were a little off. Elevator throws are 3mm up / down. Elevator is even w/ the trailing edge at full down. Ailerons are 6mm up / down.
I didn't get a chance to play w/ it too much as both Jeremy and I started racing each other right away on my maiden...
 
I was in a big hurry to finish so I just mixed some cab-o-sil and 15 min epoxy and made giant fillets on both sides of the wing joiner.
Seems to be very strong as one of my servos came unglued on a rough landing and it didn't come lose. :)
 

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So no inverted reflex? Just the camber line from the OEM airfoil? Did you guys do any inverted work? Or was the need for speed just too much.

I too need to get one of these.
 
I did some inverted flight, but as I recall it did well. The was push on the stick, but I didn’t purposely pay attention to how much. Maybe if I fly Saturday I’ll make a point to check. ?
 
Btw, I am not liking the new top skin paint job, not my style. Glad I got the older paint job. The bottom paint job is cool. I’d rather have a blank colored top then one that looks like feathers. ?
 
I'm favoring the bird look. Better to my eye than a flying bill board. I don't like the yellow as it is too close the the burned brown of the hills we fly off of. I might want a light red with feathers. I'd also like one with the part line trimmed.:rolleyes:

I'm surprised at how much time I'm spending thinking about these. Sliding trays (to shift CofG in flight) linkage set up and esthetics.

Can we ask for a special order? I'd like a bottom hinged bird.

All the best
Konrad

P.S.
I'm thinking something like this. 35° might be too much for the miniQ but I think the idea is correct for the wing. This might get the elevator response I want (elevator differential). But the aileron differential would be mechanically reversed. The aileron would need a lot of programatic correction to eliminate the adverse yaw.

Mirage 2000 airfoil 6.jpg
 
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I did some inverted flight, but as I recall it did well. The was push on the stick, but I didn’t purposely pay attention to how much. Maybe if I fly Saturday I’ll make a point to check. ?
Love the inverted emoticon!

I meant to ask, how much nose weight are you guys needing to add to reach balance?

All the best,
Konrad
 
We will have both paint schemes, so you all will be happy.

See, I do think of everything!
 
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